D.L. Knies, K.S. Grabowski, and C. CetinaNaval Research Laboratory, Washington, DC 20375

In Through the Out Door:Reconfiguring the NRL TEAMS Facility

Outline

• Introduction to TEAMS at NRL• Addition of IMS-6f• S vs. U bend and ramifications• Beam Optics for the RBS and Implant Beamlines• Conclusions

NRL TEAMS Facility

Pelletron Accelerator

C stripper foil

+ ions

SiU

30˚ Electrostatic Analyzer

3˚ Bend Selects Charge State

- ions

+3 MV

Pretzel Magnet

Mass Filter

60 keV Accel.

Sample

Switchable 45˚ electrostatic

analyzer

110 feet

27˚ BendIon Implantation

Beam Line (500 keV–12 MeV)

55˚ Bend Surface Analysis

Beam Line

Beam Line Switching Magnet

SIMS Ion Source

Plasma Ion Source (4He)

40 cathode sputtering ion

source

Key Elements of the NRL TEAMS Facility

Along with fiber optic telemetry/control and LabView user interface, provides • Stable and convenient operation.• Isotope analysis with 10-15 sensitivity (e.g., 14C)• Trace element analysis with 10-11 sensitivity for multiple elements in parallel

Input

Pretzel Magnet

Output

H Si Fe Ce USymmetry axis

Factor of 8 Mass RangeMass Resolution M/M >25001.5 Meter Focal Plane

IMS 6f as a Clean Ion Source

Current Low End Configuration

EQT

SwitchingESA

MC-SNICS

PretzelMagnet &Chopper

8 ft

Current Configuration 3º Bend for Charge State Selection

3º Bend

New Configuration 15º Bend for Charge Selection, Tank Flipped 180º

New Injector Requirements

• Maintain current capability (40-70 keV injection)

– TEAMS (MC-SNICS)– 14C AMS (MC-SNICS)– Ion Implantation (tross/MC-SNICS)– RBS and ERD (tross)– HIBS (MC-SNICS)

• Direct injection form IMS 6f (10 keV Injection)

• Variable Terminal Voltage Operation

Einzel Lenses in Tank

10 KeV to 60 KeV Injection

10 keV :1 MV

Einzel #2Einzel #1

L.E. Tube Stripper

10 KeV to 60 KeV Injection

10 keV : 2.3 MV

Einzel #2Einzel #1

L.E. Tube Stripper

10 KeV to 60 KeV Injection

40 keV :1 MV

Einzel #2

Einzel #1

L.E. Tube Stripper

10 KeV to 60 KeV Injection

60 keV :3 MV

Einzel #2

Einzel #1

L.E. Tube Stripper

SIMION 7.0 in TransportAxial Electric Field and Electric Potential

1.75" Einzel Lens

0

2000

4000

6000

8000

10000

12000

0 20 40 60 80 100 120 140

Position (mm)

Po

ten

tia

l (V

olt

s)

-500

-400

-300

-200

-100

0

100

200

300

400

500

Ele

ctr

ic F

ield

(V

/mm

)

Voltage

Electric Field

Calculated, using SIMION 7.0 Electric Fields to Model the Einzel Lenses and Accelerator Tubes in Transport.

10 KeV C- Injection to Terminal 2.7 MV

L.E. ESA

Pretzel Einzel

L.E. TubeEinzel #1

Einzel #2 Stripper

60 KeV C- Injection to Terminal 2.7 MV

Calculated, using SIMION 7.0 Electric Fields to Model the Einzel Lenses and Accelerator Tubes in Transport.

L.E. ESA

Pretzel Einzel

L.E. TubeEinzel #1

Einzel #2 Stripper

12C Optics 2.7 at High End 0.1% Momentum Spread at 2.7 MV Terminal

Calculated, using SIMION 7.0 Electric Fields to Model the Einzel Lenses and Accelerator Tubes in Transport.

H.E. Tube

Stripper

15º Bend

30º ESA

Split-Pole

HE EQT 1HE EQT 2

15º Charge State Selection

Charge State

Energy BendAngle

BeamDeflection

BeamSeparation

q MeV Degree mm mm

1 6.07 9.0 453 -308

2 9.07 12.0 607 -155

3 12.07 13.5 684 -78

4 15.07 14.4 731 -31

5 18.07 15.0 762 0

6 21.07 15.5 784 22

7 24.07 15.8 800 39

Source Voltage = 0.07 MV, Terminal Voltage = 3.00 MV, Total Plate Voltage 72.5 kV, Gap = 50 mm, Drift 2.90 M

NRL High Energy Beamline Split-pole Stripper to Split-pole

k0

3

δ

x

0

0

0

1111

111

2222

222

3

3

3

1000

0100

''/1/1

0

1000

0100

''/1/1

0

m

km

km

km

km

k

k

x

DDMf

DDM

DDMf

DDM

To form an angle- and energy-focusing spectrometer we require the image at x3 to be independent of k0.

2122120012 kkmmm DDMDDMxMM k03 δx

or 0212 kk DDM

The split-pole is a complicated magnet with,

36.033.02 M and 05.19.02/222 DDD mk

.

The -1/3 magnification requires an energy-to-charge dispersion from our high energy tube and compound ESA of ~ 2.8.

U-Bend vs. S Bend2.7 MV Terminal 12C, q3+, With and without 0.1% Momentum Spread

S-Bend 0.1 %U-Bend 0.1 %

U-Bend = 0.7 mm/%

S-Bend = 10 mm/%

Energy Dispersion

Focal Plane

S- or U-Bend no spread

U-Bend Bend

m = 0.74% and δk = 0.0%Focal Plane

m = 0.74% and δk = 0.1%

m = 0% and δk = 0.1%

m = δk = 0.0%

27º Implant Beamline2.7 MV Terminal 12C, q3+, with and without 0.1% Momentum Spread

QuadrupoleDoublet

SwitchingMagnet

QuadrupoleDoublet

Neutral TrapScanner

End Station

55º Beamline2.7 MV Terminal 12C, q3+, with and without 0.1% Momentum Spread

QuadrupoleDoublet

SwitchingMagnet

QuadrupoleDoublet

End Station

Conclusions

• New IMS-6f as TEAMS ion source• Designed injector that can do it all• Improved charge state selection• Using all-natural focusing for the AMS beamline

(removed two quads and ~10 meter of flight path)

• Designed an energy-insensitive mass focusing spectrometer

• Using Split-pole as the analyzing magnet for RBS and Implant Beamlines

Work supported by ONR and NASA